Air filtration system



FIG. 1 is a perspective view of a first embodiment of an air filtration system;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown represent unclaimed portions of the air filtration system and form no part of the claimed design. 

CLAIM The ornamental design for an air filtration system, as shown and described. 